JP2003156363A - Rotary type position detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary-type position detector, in which a magnetic rotor is rotated so as to draw a precise circle, in association with the rotation of a rotary shaft by bringing the axis of the shaft into coincidence with the rotary axis of the magnetic rotor. SOLUTION: The rotary-type position detector comprises the magnetic rotor 9, having a through hole 11a formed at a center, the rotary shaft 13 inserted into the hole 11a, a spacer 14 engaged in between the outer peripheral surface of the shaft 13 and the inner peripheral surface of the hole 11a to integrally rotate the shaft 13 with the rotor 9, and a magnetism detecting element 8, disposed near the rotor 9 to detect the magnetic field change when the rotor 9 is rotated by the rotation of the shaft 13. A tapered surface 12, inclined to the axis C2 of the shaft 13, is formed on at least one of the outer peripheral surface of the shaft 13 and the inner peripheral surface of the hole 11a, and an inclined surface 15, which is brought into contact with the tapered surface 12, is provided on the spacer 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary type position detecting device for use in power steering and attitude control systems for automobiles, etc., for detecting the rotation angle of the steering wheel or the vehicle height by converting it into a rotation angle. The present invention relates to a mounting structure inside thereof.

[0002]

2. Description of the Related Art A rotary encoder 20 will be described as an example of a conventional rotary position detecting device with reference to FIGS. 10 to 12. FIG. 10 is a sectional view of a main part of a conventional rotary encoder, and FIG. FIG. 12 is a plan view of a speed nut provided in the die encoder, and FIG. 12 is an enlarged cross-sectional view of a main part of the rotary encoder.

The main body 30 to which the rotary encoder 20 is attached is provided with a cylindrical portion 32 formed by protruding from a part of the wall portion 31 in a bottomed cylindrical shape.
A bearing portion 33, which is a ball bearing portion having a plurality of balls, is disposed inside the bearing 2. A circular through hole 32a is formed in the center of the side wall of the cylindrical portion 32.

The rotary encoder 20 includes a casing 21 having a two-stage cylindrical portion, a rotary shaft 22, a magnetic rotary body 23 that rotates together with the rotary shaft 22, and a magnetic rotary body 23 that faces the magnetic rotary body 23. Hall element 24 as a magnetic detection element arranged in parallel
And a speed nut 25 for holding the magnetic rotating body 23 so as not to fall off the rotary shaft 22.

The housing 21 is formed to have a substantially convex cross section, has an opening 21a formed in a side wall (upper side in FIG. 10), and the open side of the tubular portion is fixed to the main body 30 by an appropriate means such as caulking. ing. Further, a flat plate rectangular printed board 26 is attached to the opening 21a so as to project outward, and a hall element 24 is connected to a detection circuit (not shown) or the like in the printed board 26. Attached in the state,
The Hall element 24 is located in the opening 21a.

The rotary shaft 22 has a large diameter first shaft portion 22.
a and a second shaft portion 22b which is formed so as to project from one end of the first shaft portion 22a and has a small diameter. The first shaft portion 22a has a cylindrical portion 32a.
Is rotatably held by the bearing portion 33 while penetrating the through hole 32a of the second shaft portion 22b.
It projects from and is located inside the housing 21.

The magnetic rotating body 23 is composed of a disk-shaped permanent magnet, and has a through hole 23a formed in the center thereof. Then, in the through hole 23a of the magnetic rotating body 23, the second shaft portion 2
2b is inserted in a loosely fitted state, and one surface of the magnetic rotating body 23 is attached to the tip end surface of the first shaft portion 22a which is a step portion located at the boundary between the first and second shaft portions 22a and 22b. Abutting.

The speed nut 25 is composed of a metal circular flat plate, and as shown in FIG. 11, a disk-shaped base 25.
a and a notch 25b on both sides to form a base 25a,
Three tongue pieces 25c formed to project in the center and the base 2
It has a circular through hole 25d formed in the center of 5a. The speed nut 25 having such a structure is tightly fitted to the second shaft portion 22b and is pressed against the other surface of the magnetic rotating body 23 to prevent the magnetic rotating body 23 from coming off from the rotating shaft 22. ing. That is, the second shaft portion 22b is inserted into the through hole 25d, the base body 25a is pressed toward the first shaft portion 22a, and the magnetic rotating body 23 is sandwiched between the speed nut 25 and the first shaft portion 22a. It has become. At this time, the three tongue pieces 25c are respectively bent in the direction opposite to the pressing direction (left side in FIG. 10) to tightly fit the second shaft portion 22b. When the tongue piece 25c is tightly fitted in this way, the speed nut 25 cannot move in the axial direction, and as a result, the magnetic rotating body 23 is prevented from coming off, and the speed nut 25 and the magnetic rotating body 23 are connected to the rotating shaft 22. It will rotate together.

At this time, since the second shaft portion 22b is loosely fitted in the through hole 23a of the magnetic rotating body 23, as shown in FIG. With the speed nut 25, the axis C2 of the shaft portion 22b of the second portion is displaced in the direction orthogonal to the axial direction.
The positions of the shaft portion 22b and the magnetic rotating body 23 are determined.

Next, the operation of the conventional rotary encoder 20 will be described. When the rotary shaft 22 rotates via a steering shaft (not shown), the magnetic rotary body 23 rotates with the rotation. Then, the Hall element 24 detects a change in the magnetic field, and a magnetic detection circuit (not shown) formed on the printed circuit board 26 detects a detection pulse corresponding to the rotation of the magnetic rotating body 23. .
Then, the rotation axis C1 of the magnetic rotating body 23 and the second shaft portion 2
When the rotary shaft 22 rotates while being displaced from the axis C2 of 2b, the magnetic rotary body 23 rotates in an elliptical shape, the distance from the Hall element 24 changes, and a normal pulse cannot be detected. However, since the value is different for each rotary encoder R1, there is a possibility that the rotation angle cannot be accurately measured.

[0011]

In the conventional rotary encoder 20 described above, the speed nut 25 is
Since the second nut 22b is fitted into the second shaft portion 22b and simply abuts against the magnetic rotating body 23, the speed nut 25 and the magnetic rotating body 23 may be misaligned. When the speed nut 25 and the magnetic rotating body 23 are misaligned as described above, the positions of the axis C2 of the second shaft portion 22b and the rotating axis C1 of the magnetic rotating body 23 are not determined, and the rotating shaft 22 is rotated. Then, the magnetic rotating body 23 rotates so as to draw an ellipse, which deteriorates the performance. If it is attempted to manually correct the accuracy of the through hole 23a of the magnetic rotating body 23 and the second shaft portion 22b in order to prevent this deviation, the mass productivity deteriorates.
There is a problem of high cost. There is also a problem that the cost increases if the dimensional accuracy of both is increased.

The present invention has been made in view of the above problems, and the axis of the rotary shaft and the rotary axis of the magnetic rotary member are aligned so that the magnetic rotary member draws an accurate circle as the rotary shaft rotates. An object of the present invention is to provide a rotary type position detection device that rotates in a horizontal direction.

[0013]

In order to achieve the above object, a rotary type position detecting device of the present invention comprises a magnetic rotary member having a through hole formed in a central portion thereof and a rotary shaft inserted into the through hole. And a spacer fitted between the outer peripheral surface of the rotating shaft and the inner peripheral surface of the through hole, integrally connecting the rotating shaft and the magnetic rotating body, and arranged in the vicinity of the magnetic rotating body. And a magnetic detection element for detecting a magnetic field change when the magnetic rotating body is rotated by the rotation of the rotating shaft, and at least one of the outer peripheral surface of the rotating shaft and the inner peripheral surface of the through hole, The most main feature is that a tapered surface that is inclined with respect to the axis of the rotating shaft is formed and that the spacer is provided with an inclined surface that is in contact with the tapered surface.

Further, the rotary position detecting device of the present invention is characterized in that the spacer is formed in a ring shape surrounding the rotary shaft.

Further, in the rotary position detecting device of the present invention, the tapered surface is formed on the inner peripheral surface of the through hole so that the diameter of the through hole becomes gradually smaller toward the inside, and the outer periphery of the rotating shaft is formed. The surface is parallel to the axis, the inclined surface is provided on the outer peripheral surface of the spacer, and the inner peripheral surface of the spacer is engaged with the outer peripheral surface of the rotating shaft.

In the rotary position detecting device of the present invention, the tapered surface is formed on the outer peripheral surface of the rotary shaft and the inner peripheral surface of the through hole, and the inclined surface is formed on the inner peripheral surface of the spacer. It is characterized in that it is provided on both sides of the outer peripheral surface.

Further, the rotary position detecting device of the present invention is characterized in that the spacer is provided with a slit for elastically deforming so that the ring diameter thereof changes.

Further, the rotary position detecting device of the present invention is characterized in that a flange portion is provided at an end portion of the rotary shaft so as to come into contact with a lower end surface of the magnetic rotating body.

Further, the rotary position detecting device of the present invention is characterized in that an adhesive agent is interposed between the tapered surface and the inclined surface.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a rotary type position detecting device of the present invention will be described in detail below with reference to the drawings. Figure 1
FIG. 7 is for explaining one embodiment of the present invention. FIG. 1 is a plan view of a rotary type position detecting device according to one embodiment of the present invention, and FIG. 2 is a bottom view of the rotary type position detecting device. 3 is a sectional view of the rotary type position detecting device, FIG. 4 is a bottom view showing the lower lid and the rotary shaft from FIG. 2, FIG. 5 is an enlarged sectional view of an essential part of FIG. 3, and FIG. FIG. 7 is a perspective view of a spacer included in the position detecting device, and FIG. 7 is an enlarged cross-sectional view of a main part when the rotary shaft included in the rotary type position detecting device has a small shaft diameter.

The housing 1 is made of a synthetic resin molded product, and is composed of a base body 2 and a lower lid 3 which is a ring-shaped flat plate snap-fitted to the base body 2. The base body 2 is composed of a cylindrical housing portion 4 having a ring-shaped wall portion having a U-shaped cross section, and an elongated rectangular connector portion 5 that is connected to a side edge of the housing portion 4 and projects outward. ing. The storage portion 4 includes an outer wall 4a having a large diameter, an inner wall 4b having a small diameter, and a flat plate-shaped wall portion 4d connecting the outer wall 4a and the inner wall 4b and having a hole 4c in the central portion. It is configured. Inner wall 4
Referring to FIG. 4, a concave portion 4e is formed by cutting out two places in b. In addition, a receiving portion 5 a formed of a rectangular recess is formed in the connector portion 5 toward the storage portion 4. In addition, the claw receiving hole 4f is provided at the edge of the outer wall 4a.
Is provided.

The lower lid 3 is made of a synthetic resin ring-shaped flat plate, and the central portion having the hole 3a is recessed in a ring shape. The lower lid 3 is snap-coupled and fixed so as to cover the open side of the storage section 4. That is, by covering the storage part 4 with the lower lid 3 from the open side of the storage part 4, the claws of the mounting legs (not shown) that are provided upright on the outer peripheral edge of the lower cover 3 engage with the claw receiving holes 4f. , Snap connection is made. When the lower lid 3 is snap-fitted, a donut-shaped hollow portion 4g is formed between the lower lid 3 and the inner and outer walls 4b, 4a of the storage portion 4, and the inner wall 4b and the inner wall 4b are covered. A recess 4h for storage is formed with the lid 3, and the recess 4h is in a state in which the upper and lower sides thereof are opened by the holes 4c and 3a.

The printed circuit board 6 is made of a fan-shaped and rigid plate-shaped rigid insulating substrate, and the connector portion 5 has four terminals 7 bent at 90 degrees. One end of the terminal 7 is soldered while penetrating the printed board 6, and the other end projects into the receiving portion 5a. Also, in FIG.
As shown in FIG. 4, a Hall element 8 which is a magnetic detection element is vertically attached to the printed circuit board 6 by an appropriate means such as soldering on the inner side of the printed circuit board 6. The printed circuit board 6 is fixed in the hollow portion 4g of the housing portion 4 in a state of being soldered to the four terminals 7 embedded in the connector portion 5. The hall element 8
As shown in FIGS. 3 and 4, the is housed in the concave portion 4e of the inner wall 4b and is exposed on the side of the recess 4h.

The magnetic rotating body 9 is formed by molding a ring-shaped permanent magnet 10 such as a plastic magnet with a molding material 11 such as a synthetic resin to form a cylindrical shape, and has a through hole 11a at the center thereof. The permanent magnet 10 is magnetized so that N poles and S poles alternate in the circumferential direction, and as shown in FIG. 5, the diameter of the through hole 11a is smaller than the diameter of the through hole 11a on the inner peripheral surface of the through hole 11a. A mortar-shaped tapered surface 12 is formed so as to become gradually smaller toward the inside. In addition, the ring-shaped convex portion 1 is provided on the upper surface and the lower surface of the permanent magnet 10.
0a is formed, the permanent magnet 10 is surely fixed to the molding material 1 even if the magnetic rotating body 9 rotates at a high speed and a large centrifugal force is applied.
1, and the permanent magnet 10 and the molding material 11 can be prevented from peeling off.

The magnetic rotating member 9 thus integrated with the permanent magnet 10 is housed in the recess 4h of the housing 1,
It faces the inner wall 4b. At this time, the magnetic rotating body 9 is positioned so that the permanent magnet 10 is at the same height as the Hall element 8, and a part of the permanent magnet 10 is housed in the concave portion 4e as shown in FIG. 8 will be opposed. The magnetic rotating body 9 integrated with the permanent magnet 10 housed in such a state is rotatable within the recess 4h, and changes in the magnetic field of the permanent magnet 10 rotating together with the magnetic rotating body 9 are prevented. The Hall element 8 is adapted to read.

The rotary shaft 13 is made of a metal material, and is made of sintered metal in the present embodiment, and has a shaft hole 13 at the center.
It has a cylindrical shape in which a is formed, and the outer peripheral surface is the rotating shaft 1.
The flange 13b is formed in parallel with the axis C2 of 3 and has a disc-shaped flange at its end. Such a rotating shaft 13 is inserted into the through hole 11a of the magnetic rotating body 9, and the flange portion 13b is in contact with the lower end surface of the magnetic rotating body 9. The tapered surface 12 is in an inclined state.

The spacer 14 is formed of a synthetic resin material or the like in a ring shape. As shown in FIG. 6, a part is cut out to form a slit 14a and a flange portion 14b is formed on the upper end portion. The inclined surface 15 is formed on the outer peripheral surface along the entire circumference, and the entire surface is formed to have a wedge-shaped cross-section that is thinner toward the lower end. The spacer 14 is formed by inserting the rotating shaft 13 into the inner peripheral side of the rotating shaft 13.
Outer peripheral surface and the tapered surface 12 of the through hole 11a of the magnetic rotating body 9.
The rotary shaft 13 and the magnetic rotary body 9 are integrally connected by being fitted between the inner peripheral surface of the spacer 14 and the outer peripheral surface of the rotary shaft 13 so as to come into contact with each other. The inclined surface 15 is in surface-to-surface contact with and abuts the tapered surface 12 of the magnetic rotating body 9. Therefore, the magnetic rotating body 9 can be stably held on the rotating shaft 13.

By the way, since the rotary shaft 13 is made of a sintered metal and has sufficient strength and can be manufactured at a relatively low cost, the diameter dimension is apt to vary, and the magnetic rotary member 9 is easily manufactured.
When the gap between the inner peripheral surface of and the outer peripheral surface of the rotating shaft 13 is large,
In some cases, the rotation axis C1 of the magnetic rotating body 9 may be displaced from the axis C2 of the rotation shaft 13 in some cases. However, the inner peripheral surface of the through hole 23 a of the magnetic rotating body 20 is formed into a mortar-shaped tapered surface 12, and the spacer 14 has a tapered surface 12.
Since the inclined surface 15 and the slit 14a that come into surface contact with and come into contact with the slit 14a are formed, when the diameter of the rotary shaft 13 is small,
When the spacer 14 is pressed and fitted between the outer peripheral surface of the rotating shaft 13 and the tapered surface 12 of the through hole 11a of the magnetic rotating body 9, the slit 14a is narrowed by the contact between the tapered surface 12 and the inclined surface 15. The spacer 14 elastically deforms to a small diameter, and the rotation shaft 13 follows this deformation.
7 and the taper surface 12 of the magnetic rotating body 9 are evenly spaced over the entire circumference. As shown in FIG.
Is located lower than that shown in FIG. 5, and the axis C2 of the rotary shaft 13 coincides with the axis C1 of rotation of the magnetic rotor 9.

When the diameter of the rotary shaft 13 is large, the outer peripheral surface of the rotary shaft 13 and the through hole 11a of the magnetic rotor 9 are formed.
When the spacer 14 is fitted between the tapered surface 12 of
Since the spacer 14 is elastically deformed to a large diameter by the rotating shaft 13 fitted on the inner peripheral side and the tapered surface 12 and the inclined surface 15 are engaged with each other, as shown in FIG. Is also located above, and the rotation axis C1 of the magnetic rotor 9 is
The axis C2 of the rotary shaft 13 coincides with.

When the spacer 14 is fitted, since the lower end surface of the magnetic rotating body 9 is in contact with the flange portion 13b of the rotating shaft 13, the magnetic rotating body 9 moves in the direction of the axis C2 of the rotating shaft 13. Can be regulated, the fitting work of the spacer 14 can be performed smoothly, and the inclination of the magnetic rotating body 9 with respect to the axis C2 of the rotating shaft 13 can be suppressed.

After the spacer 14 is fitted, since the inner peripheral surface of the spacer 14 is engaged with the outer peripheral surface of the rotary shaft 13 which is a rough surface having a high friction coefficient, the spacer 14 is separated from the rotary shaft 13. Since the falling surface can be prevented and the inclined surface 15 of the spacer 14 acts to press the tapered surface 12 of the magnetic rotating body 9 and press the magnetic rotating body 9 against the flange portion 13b of the rotating shaft 13, the magnetic rotating body 9 is rotated. The shaft 13 can be held securely.

In this embodiment, the outer peripheral surface of the rotary shaft 13 and the inner peripheral surface of the spacer 14 are in surface contact with each other so that they come into contact with each other. Even if it is inserted, it is corrected with the insertion so that the most stable surface contact state is achieved. The same can be said for the outer peripheral surface of the spacer 14 and the inner peripheral surface of the magnetic rotating body 9. Therefore, with these configurations, the magnetic rotating body 9 is held without tilting with respect to the rotating shaft 13.

Further, in this embodiment, the lower surface of the magnetic rotary member 9 is brought into contact with the flange portion 13b, and tilting is prevented even in this portion, so that the rotary shaft 1 can be more reliably and easily.
The magnetic rotating body 9 is held without being inclined with respect to 3,
The collar portion 13b may be omitted.

In this embodiment, the spacer 14 has a small diameter when the diameter of the rotating shaft 13 is small, but the diameter of the spacer 14 is always smaller than that of the rotating shaft 13. You may create it. By doing so, the spacer 14 is deformed into a large diameter so that the surface of the spacer 14 and the surface of the rotating shaft 13 come into close contact with each other. Therefore, the spacer 14 is guided by the rotating shaft 13 and pushed in without tilting. This is possible by holding 9 on the rotating shaft 13 without tilting.

Next, the operation of the rotary type position detecting device of the present invention configured as described above will be described with reference to FIG. This rotary position detecting device is used in a state in which a shaft 16 such as a worm gear connected to a steering shaft as a drive source is press-fitted into a shaft hole 13a of the rotary shaft 13 and the shaft 16 is fixed to the rotary shaft 13. .

When the shaft 16 is rotated by the rotation of a steering shaft (not shown), the rotary shaft 13 is rotated along with the rotation. When the rotating shaft 13 rotates, the magnetic rotating body 9 rotates together. Then, the change of the magnetic field is detected by the two Hall elements 8 and two-phase sine waves are output, and the permanent magnet 10 of the magnetic rotating body 9 is output by the CPU or the like (not shown) formed on the printed circuit board 6. The detection pulse corresponding to the rotation of is detected and output as an electric signal from the terminal 7.

In this embodiment, the spacer 1
In order to prevent the fitting workability of No. 4 from being deteriorated, the spacer 14 is formed in a series of ring shapes and can be handled as an integrated product. However, for example, the spacer 14 is divided at intervals of 120 degrees. The spacer 14 may be composed of three pieces, and the spacer 14 can be modified in various ways such as being composed of a plurality of pieces in addition to the ring-shaped integrated product.

Further, in this embodiment, the inclined surface 15 of the spacer 14 is brought into contact with the tapered surface 12 of the magnetic rotating body 9 by surface contact, but the tapered surface 12 and the inclined surface 1
It is also possible to provide a plurality of small projections on one of the five and make the plurality of small projections contact the tapered surface 12 and the other of the inclined surfaces 15 by point contact. That is, according to the present invention, it is sufficient that the both members are allowed to slide only in the plane direction.
Two surfaces may be formed.

Further, if an adhesive agent is interposed between the tapered surface 12 and the inclined surface 15 and the tapered surface 12 and the inclined surface 15 are bonded with this adhesive agent, the magnetic rotating body 9 can be held more reliably. can do.

In the embodiment shown in FIG. 8, instead of forming the tapered surface 12 on the magnetic rotating body 9 and providing the inclined surface 15 on the spacer 14, the outer peripheral surface of the rotating shaft 13 is chamfered over the entire circumference to form a taper. The magnetic rotor 9 and the spacer 14 and the rotary shaft 13 in the case where the surface 13c is formed and the inclined surface 14d is formed on the inner peripheral surface of the spacer 14 over the entire circumference are enlarged cross-sectional views of the main parts. The configuration is similar to that of the above-described embodiment. Even in this case, the rotation axis C of the magnetic rotating body 9
The axis C2 of the rotary shaft 13 can be aligned with 1.

Further, in the embodiment shown in FIG. 9, the tapered surface 12 is formed on the inner peripheral surface of the through hole 11a of the magnetic rotor 9.
An inclined surface 15 is provided on the outer peripheral surface of the spacer 14 over the entire circumference, and further chamfering is performed on the outer peripheral surface of the rotary shaft 13 to form a tapered surface 13d, and an inner peripheral surface of the spacer 14 is formed over the entire peripheral surface. Inclined surface 14c that abuts the tapered surface 13d over
9 is an enlarged cross-sectional view of a main part of the magnetic rotating body 9, the spacer 14 and the rotating shaft 13 in the case where the above is formed. Also in this case, the axis C2 of the rotary shaft 13 can be aligned with the rotary axis C1 of the magnetic rotating body 9, and the taper having a large diameter on the insertion side of the spacer 14 formed on the outer peripheral surface of the rotary shaft 13 can be obtained. Surface 13d
And the inclined surface 14c formed on the inner peripheral surface of the spacer 14 increase the contact area between the rotary shaft 13 and the spacer 14, and the spacer 14 is blocked by the rotary shaft 13 in the direction in which the spacer 14 is inserted. It is possible to reliably prevent the rotary shaft 13 from falling off.

[0042]

The present invention is carried out in the form as described above, and has the following effects.

In the rotary position detecting device of the present invention, at least one of the outer peripheral surface of the rotating shaft and the inner peripheral surface of the through hole of the magnetic rotating body is formed with a taper surface inclined with respect to the axis of the rotating shaft. Since the spacer fitted between the outer peripheral surface of the rotating shaft and the inner peripheral surface of the through hole is provided with an inclined surface that abuts the tapered surface, the rotation axis of the magnetic rotating body is rotated. To provide a high-performance rotary position detecting device that can match the axis lines of the shafts, and that the magnetic rotating body rotates so as to draw an accurate circle in accordance with the rotation of the rotating shaft and outputs a desired output. You can

Further, since the spacer is formed in a ring shape surrounding the rotary shaft, the spacer can be easily handled and the assembly workability can be prevented from being deteriorated.

Further, the tapered surface is formed on the inner peripheral surface of the through hole so that the diameter of the through hole becomes gradually smaller toward the inside, and the outer peripheral surface of the rotating shaft is made parallel to the axis line. Since the inclined surface is provided on the outer peripheral surface of the spacer and the inner peripheral surface of the spacer is engaged with the outer peripheral surface of the rotating shaft,
Since the tapered surface can be pressed by the inclined surface, it is possible to prevent the spacer from slipping off from the rotating shaft, and it is possible to reliably hold the magnetic rotating body on the rotating shaft.

Further, since the tapered surfaces are formed on the outer peripheral surface of the rotary shaft and the inner peripheral surface of the through hole, respectively, and the inclined surfaces are provided on both the inner peripheral surface and the outer peripheral surface of the spacer, It is possible to more reliably prevent the spacer from coming off the rotation shaft due to an increase in the contact area between the rotation shaft and the spacer.

Since the spacer is provided with a slit for elastically deforming so that the ring diameter changes, even if the diameter of the rotating shaft varies, the rotating shaft line of the magnetic rotating body is not affected. The axes of the rotating shafts can be aligned.

Since the end of the rotating shaft is provided with a flange portion that comes into contact with the lower end surface of the magnetic rotating body, the magnetic rotating body is restricted from moving in the axial direction of the rotating shaft. Therefore, it is possible to smoothly perform the fitting work of the spacer, and it is possible to suppress the inclination of the magnetic rotating body with respect to the axis of the rotating shaft.

Since the adhesive is interposed between the tapered surface and the inclined surface, the magnetic rotating body can be held more reliably.

[Brief description of drawings]

FIG. 1 is a plan view of a rotary position detecting device according to an embodiment of the present invention.

FIG. 2 is a bottom view of the rotary position detector.

FIG. 3 is a cross-sectional view of the rotary position detector.

FIG. 4 is a bottom view showing a lower lid and a rotary shaft removed from FIG.

5 is an enlarged cross-sectional view of a main part of FIG.

FIG. 6 is a perspective view of a spacer included in the rotary type position detection device.

FIG. 7 is an enlarged cross-sectional view of a main part when a shaft diameter of a rotary shaft included in the rotary position detecting device is small.

FIG. 8 is an enlarged sectional view of an essential part for explaining a modified example of the present invention.

FIG. 9 is an enlarged sectional view of an essential part for explaining another modification of the present invention.

FIG. 10 is a sectional view of a main part of a conventional rotary encoder.

FIG. 11 is a plan view of a speed nut provided in a conventional rotary encoder.

FIG. 12 is a sectional view of a main part of a conventional rotary encoder.

[Explanation of symbols]

1 case 2 base 3 Lower lid 3a hole 4 storage 4a outer wall 4b inner wall 4c hole 4d wall 4e concave part 4f claw receiving hole 4g hollow part 4h depression 5 Connector part 5a Receiver 6 printed circuit boards 7 terminals 8 Hall element 9 Magnetic rotating body 10 permanent magnet 10a convex part 11 Mold material 11a through hole 12 Tapered surface 13 rotation axis 13a shaft hole 13b collar part 13c Tapered surface 13d taper surface 14 Spacer 14a slit 14b Flange part 14c slope 14d taper surface 15 inclined surface 16 shafts

Claims (7)

[Claims] 1. A magnetic rotating body having a through hole formed in a central portion thereof, a rotary shaft inserted into the through hole, and an outer peripheral surface of the rotary shaft and an inner peripheral surface of the through hole. And a spacer that integrally connects the rotating shaft and the magnetic rotating body, and is arranged in the vicinity of the magnetic rotating body, and detects a magnetic field change when the magnetic rotating body rotates due to rotation of the rotating shaft. A magnetic detection element, a taper surface that is inclined with respect to the axis of the rotating shaft is formed on at least one of the outer peripheral surface of the rotating shaft and the inner peripheral surface of the through hole, and the taper is formed on the spacer. A rotary type position detecting device, characterized in that an inclined surface that comes into contact with the surface is provided. 2. The rotary type position detecting device according to claim 1, wherein the spacer is formed in a ring shape surrounding the rotation shaft. 3. The tapered surface is formed on the inner peripheral surface of the through hole so that the diameter of the through hole becomes gradually smaller toward the inside, and the outer peripheral surface of the rotary shaft is parallel to the axis. The rotary position detecting device according to claim 2, wherein the inclined surface is provided on the outer peripheral surface of the spacer, and the inner peripheral surface of the spacer is engaged with the outer peripheral surface of the rotating shaft. 4. The tapered surface is formed on each of the outer peripheral surface of the rotating shaft and the inner peripheral surface of the through hole, and the inclined surfaces are provided on both the inner peripheral surface and the outer peripheral surface of the spacer. The rotary position detecting device according to claim 2, which is characterized in that. 5. The rotary position detecting device according to claim 2, wherein the spacer is provided with a slit that is elastically deformable so that the ring diameter changes. 6. The rotary die according to claim 1, 2, 3, 4 or 5, wherein a flange portion is provided at an end portion of the rotary shaft so as to come into contact with a lower end surface of the magnetic rotating body. Position detection device. 7. The adhesive agent is interposed between the tapered surface and the inclined surface.
The rotary position detection device according to 4, 5, or 6.